Matherville, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.7 °C (low) to 15.5 °C (high). Annual precipitation averages 964.4 Millimeters. Matherville is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.9 °C | -0.9 °C | 39.88 mm |
| February | -8 °C | 1.6 °C | 45.97 mm |
| March | -2.1 °C | 9 °C | 61.72 mm |
| April | 4 °C | 16.3 °C | 96.01 mm |
| May | 10.7 °C | 22.3 °C | 124.97 mm |
| June | 16.1 °C | 27.3 °C | 121.16 mm |
| July | 18.1 °C | 29 °C | 102.36 mm |
| August | 16.9 °C | 28 °C | 97.54 mm |
| September | 12.3 °C | 24.7 °C | 93.22 mm |
| October | 5.8 °C | 17.6 °C | 72.64 mm |
| November | -0.8 °C | 9.3 °C | 58.93 mm |
| December | -6.6 °C | 2.2 °C | 50.04 mm |
| Annual | 4.7 °C | 15.5 °C | 964.44 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |